This invention relates to toner dispensers for electrostatic processors and, more particularly, to methods and means for improving the performance of toner dispensers having rotatably driven dispensing rolls. Even more specifically, the present invention pertains to enhancements for toner dispensers of the type that have a brush-like wiper for dislodging toner particles from a rotatably driven, grooved dispensing roll.
As a general rule, development system for continuous electrostatic processors employ a multi-component developer and include a toner dispenser for adding additional toner to the developer from time-to-time. Some toner is, of course, necessarily consumed in the development process and the additional toner is, therefore, needed to maintain the toner concentration of the developer at a suitably high level.
Unfortunately, conventional toner compositions are tacky, especially when exposed to heat or high humidity. That characteristic is one of the more common sources of problems with toner dispensers. For example, in toner dispensers which have rotatably driven dispensing rolls, agglomerated masses of toner sometimes form so-called bridges in the immediate area of the dispensing roll, thereby interfering with the flow of toner. Additionally, in those toner dispensers which have a grooved dispensing roll for supplying metered amounts of toner and a brush-like wiper for dislodging the toner from the dispensing roll, there sometimes is a tendency for toner to accumulate in the grooved areas of the roll, thereby upsetting the metering action.